Device and method for aligning containers

Abstract

A device and a method for aligning containers including an evaluation unit, which is capable of determining the position and/or the rotary position of at least one feature of the surface of containers to be aligned, by calculating image data of said feature in at least two views that differ with respect to the imaged rotary position of the containers, and where picture distortions and contrast limitations caused by the perspective can be compensated. The reliability of rotary position recognition and correction can thus be improved when aligning the containers.

What is claimed is: 
     
       1. A device for aligning containers, comprising:
 rotatable holders for holding and individually rotating the containers; 
 at least two cameras provided along a conveying path for the containers for imaging the containers in a plurality of views differing from one another with respect to the imaged rotary position of the containers, thereby imaging at least one feature of the containers at different object angles and creating different image data of the feature by the cameras; 
 an evaluation unit for determining the position of the features on the surface of the containers on the basis of these views, and 
 the evaluation unit being configured to be capable of determining at least one of the position or the rotary position of the feature of the surface of the container by at least one of mutually calculating and comparing the different image data of the feature in at least two of the views. 
 
     
     
       2. The device according to  claim 1 , the cameras being arranged such that object angles (α 1 , α 2 ) of areas of the feature, which correspond to one another in the at least two views, differ from one another by at least 30°. 
     
     
       3. The device according to  claim 2 , and the object angles differing from one another by at least 45°. 
     
     
       4. The device according to  claim 1 , and the evaluation unit being configured to be capable of creating from the image data of the at least two views a virtual view of the container. 
     
     
       5. The device according to  claim 1 , and the cameras have at least one image area overlapping along the conveying path, so as to image the feature in the overlapping image area under different object angles (α 1 , α 2 ). 
     
     
       6. The device according to  claim 5 , and a plurality of overlapping image areas is provided along the conveying path, so as to image the container in the overlapping image areas in a full-circumference imaging mode. 
     
     
       7. The device according to  claim 1 , further comprising an illumination unit for illuminating the containers to create different shadows and/or reflection patterns at the feature in said at least two views. 
     
     
       8. The device according to  claim 7 , the illumination unit comprising a direction illumination unit. 
     
     
       9. The device according  claim 1 , further comprising a control unit for aligning the rotary position of the containers on the basis of the determined position and/or determined rotary position of said feature. 
     
     
       10. A labeling machine including the device according to  claim 1 . 
     
     
       11. A method of aligning containers, comprising:
 a) conveying and rotating the containers; 
 b) imaging the containers from at least two different camera positions so as to image a circumferential area of each of the containers in at least two views differing with respect to the imaged rotary position of the respective container thereby imaging at least one feature of the containers at different object angles and creating different image data of the feature; and 
 c) determining the position and/or the rotary position of the feature of the surface of the container by at least one of mutually calculating and comparing the different image data of the feature in the at least two views. 
 
     
     
       12. The method according to  claim 11 , the image data of the at least two views being interpolated and/or added in step c). 
     
     
       13. The method according to  claim 11 , and creating a virtual view of the container from the image data of the at least two views in step c). 
     
     
       14. The method according to  claim 11 , the at least two views including an overlapping image area and being imaged substantially simultaneously. 
     
     
       15. The method according to  claim 11 , further comprising determining an actual rotary position of the containers on the basis of the position and/or rotary position of the least one feature determined in step c), and of ascertaining a rotary position correction for moving the container to a target rotary position. 
     
     
       16. The method according to  claim 15 , further comprising moving the container to the target rotary position. 
     
     
       17. The method according to  claim 16 , and labeling the containers where the accessed target rotary position comprises a starting position and/or reference position for labeling.